The goal of the Molecular Mechanisms of Toxicity Training Program is to provide students with an education in toxicology that is based on an understanding of biochemistry, physiology, pharmacology and molecular/cell biology, coupled with an in-depth research experience on the mechanisms by which specific agents induce toxicity, and/or the basic cellular processes upon which environmental agents impact to cause toxicity. The Training Program is based in the Graduate Center for Toxicology (GCT) which grants the Ph.D. in Toxicology, and provides an administrative and teaching nucleus of 6 core faculty. The diversity of training opportunities is enhanced by 24 joint faculty who have primary appointments in the Colleges of Medicine, Pharmacy, Agriculture and Arts &Sciences, and Nutritional Sciences. Numerous collaborations and multidisciplinary approaches to research problems among this group provide a rich research training environment. This application requests support for 8 predoctoral trainees in five areas of strength which serve as a focus: 1) Oxidative Stress, 2) DNA Repair, 3) Biochemical Toxicology, 4) Neurotoxicology and 5) Immunotoxicology. Current enrollment in the Toxicology Program is 35 predoctoral students, including 5 minority students. The University of Kentucky sponsors a program with the University of Puerto Rico to bring up to 10 students for summer research experiences as a means of increasing our recruitment of outstanding minority doctoral students;6-7 of these students work in the laboratories of GCT faculty and 5 are supported by a T35 Environmental Toxicology/Short Term Research Grant (ES 10951). The predoctoral training program requires 23 credit hours in biomedical based coursework (i.e., biochemistry, physiology, cell biology, pharmacology, statistics), 13 in toxicology-based courses (including Ethics in Scientific Research) and two electives (3-4 credits) selected from courses germane to the research area (e.g., molecular biology, neuroscience, immunology). Students are guided through the program initially by a Director of Graduate Studies, followed by a Major Advisor and a 4-member Advisory Committee, which supervises the student's Qualifying Examination, research and thesis defense. There continues to be strong University support for the GCT in the form of student fellowships, supplementation of the Training Grant, and new faculty lines, space and equipment. The program continues to grow in terms of the quality and breadth of the Training Program due to recruitment of new faculty with vigorous research programs, increased funding of faculty and increased enrollment of excellent, motivated predoctoral students.